Blender 2.79 Rigging - Dependency cycle help
The problem is that the wristmarker is an empty object. You can make it a bone and give it a custom shape.

Blender has a limitaion with cycle evaluation on object level, something that even new dependency graph does not solve. This does not exist in Maya, Cinema 4D, etc., where you would use empties in rigging.

In Blender it is convenient to keep all the relations inside the armature object. If you link something to an empty and back to the same rig, it will create dependency on object level.

If you really need to constraint or parent to different object (like when using curves and spline IK), you cannot link back to the same rig, but you have to use a different one to stay clear of any dependency cycles. This can be solved like this:

Rigging question about Spline IK and having all controls on one armature

Another reason to use only bones for any controls the animator will interact with is for linking characters into another .blend files. This also does not work conveniently as in other apps, you have to create a proxy object from your armature. If you had the rig setup with empties outside the armature, your rig would fall apart when making that proxy.